MOS2 Spectrum for observation 0085150101 (see Table A.1) accumulated over the entire FOV. Top panel: observed spectrum (data points) and spectral model comprising a QPB component (broken power law, shown as a dashed red line, and Gaussian lines, shown as dashed blue lines) and a QSP component (broken power law, shown as a dashed black line). The fit is performed in the [4−10] keV energy range and extrapolated to lower energies. Parameters for the QPB component are fixed to the value estimated from filter-wheel-closed data. The contribution of the QSP component increases with respect to that of the QPB as we move down in energy. Bottom panel: residuals in the form of ratio of data over model; in the [0.7−1.2] keV band the data exceeds the model by a factor of 2, indicating that in this range roughly half of the accumulated events come from the X-ray sky and the other half are associated with particles.